Arild Hermstad, leader of activists Future in Our Hands hailed Oslo’s decision as a “brave move” weeks before a UN climate summit in Paris, and said the city council would work with other funds to invest ethically.

He said: “There’s a strong symbolism when the capital city of our oil producing nation says “No” to investing in fossil fuels. It shows that fossil fuels are history, and that shifting away from them, and towards renewables, is the future.”

Nguyen Berg said it was a “sound financial decision” given the effect of slumped energy prices on the economy which last year relied on oil and gas sales for 45% of export revenue.

“This policy change will protect our pensions from being invested in stranded assets.”